Student activists on the radical fringe of the campaign against the government's education cuts will be the target of a national police intelligence operation, it emerged .

Speaking on the eve of a student day of action, the officer in charge of monitoring "domestic extremism" in the UK said his officers' focus was on the "fringe" where protest "spills over" into violence and disorder.

"It is quite right in our role as Acpo [Association of Chief Police Officers] goalkeeper to watch where the social protests are going and how they are developing and to try, where possible, to identify flashpoints," said Detective Chief Superintendent Adrian Tudway, who took over the role of national co-ordinator for domestic extremism last week.

Asked if more work was being done in the wake of the protest this month which saw 50,000 students take to the streets of London and ended in violence when some stormed Conservative party headquarters, Tudway replied: "Absolutely."

The comments came before a national day of action which is expected to see thousands of people on the streets for the second time in a fortnight in protest at plans to raise tuition fees and scrap the education maintenance allowance.

Tonight more than 22,000 school, college and university students had signed up to a Facebook site organising a co-ordinated "walkout" from classes at 11am . Scores more regional groups have sprung up and are organising their own events, amid signs that the scale of the London protest has emboldened the wider student movement.

This evening an effigy of Nick Clegg was hanged and set on fire outside the Guardian offices in north London, where the deputy prime minister was delivering the Hugo Young lecture.

Students from the School of Oriental and African Studies, London School of Economics and Westminster Kingsway College were joined by protesters from the Socialist Workers party, Right to Work and the Government of the Dead. There were chants of "Nick Clegg, shame on you for turning blue" as police officers looked on.

Students from Westminster Kingsway held a banner saying: "Education is our right, take it away and we will fight."

Pablo, 18, studying A-levels at Westminster Kingsway, said: "I am one of the students that voted for him [Clegg] to get in power, we feel betrayed. They think the students are passive, no we're not. We're going to come out in numbers tomorrow and join the demo."

Chris Knight, a former university lecturer from the Government of the Dead, said it had hanged an effigy of Clegg because it was a crime that the government had enough money to bail out Irish banks but not to help students.

"He knew perfectly well two months before the election he had no intention of abolishing student fees," he said. They were able to form this rotten ConDem government on the basis of cheating, I can't think of any worse crime."

Many of the largest demonstrations are expected in cities with big student populations, such as Leeds, Liverpool, Manchester and London, But hundreds of students – many of them sixth formers or further education students – have also organised protests in towns across the UK. In Bury, 1,200 people have signed up on Facebook to say they are planning to join the walkout; in Milton Keynes 600 people have signed up and a similar number have said they are taking part in Colchester and Bournemouth.

"We have been amazed by the response," said Jake Deans, 17, who helped organised a walkout and demonstration in Bournemouth. "Me and a few friends thought we would stand outside our college with a banner or something but once we set up the Facebook page it has got bigger and bigger. We are hoping for more than 1,000 people now and the police have agreed to close off some streets for the march to the town hall.

Deans, a student at St Peter's in Bournemouth, said school and sixth form students, who are expected to make up about half of tomorrow's demonstration, are becoming increasingly angry at the government's plans.

"Everything that the government is planning to do is going to make it harder and more expensive to go to uni and I don't think that is fair for this generation."Tonight a sit-in at the School of Oriental and African Studies was entering its second day, with students saying talks with the management had broken down.